If the person has hurt the company, then the company must take action, not you. You cannot sue for remarks about your family. You must be able to prove harassment and document, by way of medical and/or psychiatric records, how you were badly affected.

Harassment really varies, from town, and state. In many places it must be sexual in nature, or not regulated at all. You really need to go to your supervisor, HR, and keep going up the line and document everything. Consult your police. If you perceive a threat, CALL THE POLICE.